[0161]Meanwhile, in Examples B1 to B5 and Comparative Examples B1 to B6, blackening of an appearance of the above-described silver-plated reflector (corrosion (blackening discoloration) of silver plate by sulfur gas) was observed through visual inspection and evaluated in terms of a time required for reaching the same degree as that in a separately fabricated standard plate (plate prepared by blackening a silver-plated reflector directly with a sulfur gas). Incidentally, the lower the gas barrier properties of the composite, the shorter the time required for reaching blackening was.
(Hardness Evaluation of Silicone Resin Composite)
[0162]With respect to the hardness evaluation of a silicone resin composite, at the time of fabricating a silicone resin composite, the case where no crack was generated was defined as “A”, and the case where a crack was generated was defined as “B” (Examples B1 to B5 and Comparative Examples B1 to B6).
(Thickness of Sealing Layer Made of Silicone Resin Composite)
[0163]A thickness of a sealing layer made of a silicone resin composite was measured by observing a cross section of the above-described package by SEM.
Example A1
Fabrication of Zirconia Particle
[0164]To a zirconium salt solution of 2,615 g of zirconium oxychloride octahydrate dissolved in 40 L (liters) of pure water, dilute ammonia water of 344 g of 28% ammonia water dissolved in 20 L of pure water was added while stirring, thereby preparing a zirconia precursor slurry.
[0165]Subsequently, a sodium sulfate aqueous solution of 300 g of sodium sulfate dissolved in 5 L of pure water was added to this slurry while stirring. At this time, the addition amount of sodium sulfate was 30% by mass relative to a zirconia conversion value of a zirconium ion in the zirconium salt solution.
[0166]Subsequently, this mixture was dried in the air at 130° C. for 24 hours by using a dryer, thereby obtaining a solid.
[0167]Subsequently, this solid was pulverized by an automatic mortar and then baked in the air at 500° C. for one hour by using an electric furnace.
[0168]Subsequently, this baked material was put into pure water and stirred to make into a slurry form. Thereafter, cleaning was performed using a centrifugal separator, and the added sodium sulfate was sufficiently removed, followed by drying with a dryer, thereby obtaining a zirconia particle having an average primary particle diameter of 4 nm.
(Surface Modification on Zirconia Particle: Fabrication of Surface-Modified Zirconia Particle)
[0169]Subsequently, to 10 g of the zirconia particle, 82 g of toluene and 5 g of a methoxy group-containing phenyl silicone resin (KR217, manufactured by Shin-Etsu Chemical Co., Ltd.) were added and mixed, and the mixture was subjected to a surface modification treatment with a bead mill for 6 hours, followed by removing the beads. Subsequently, 3 g of vinyltrimethoxysilane (KBM1003, manufactured by Shin-Etsu Chemical Co., Ltd.) was added, and the contents were subjected to surface modification and dispersion treatment under refluxing at 130° C. for 6 hours, thereby preparing a transparent dispersion liquid of zirconia particle having been surface-modified with a surface-modifying material having a phenyl group and a surface-modifying material having a vinyl group that is an alkenyl group.
(Fabrication of Silicone Resin Composition)
[0170]To 50 g of the above-described transparent dispersion liquid of zirconia particle, 7.6 g of, as a phenyl silicone resin, a trade name: OE-6520 (manufactured by Dow Corning Toray Co., Ltd., refractive index: 1.54, compounding ratio of liquid A/liquid B=1/1) (liquid A: 3.8 g, liquid B: 3.8 g) was added, and after stirring, the toluene was removed by drying under reduced pressure, thereby obtaining a silicone resin composition containing a surface-modified zirconia particle, a phenyl silicone resin, and a reaction catalyst (zirconia particle content: 30% by mass).
[0171]Incidentally, with respect to OE-6520, not only the presence of an Si—H bond is already confirmed by means of an NMR analysis, but also it is already grasped that a hydrogen group is contained in the silicone resin-forming component. In consequence, OE-6520 can be integrated with the vinyl group (alkenyl group) of vinyltrimethoxysilane that surface-modifies the zirconia particle through a crosslinking reaction.
[0172]In addition, with respect to OE-6520, not only the presence of a C═C double bond (vinyl group) that is an alkenyl group is already confirmed by means of an NMR analysis, but also the presence of platinum is already confirmed by means of an emission analysis. That is, OE-6520 is a silicone resin of an addition curing type, which is polymerized and cured by means of an addition reaction (hydrosilylation reaction). In consequence, it can be understood that in OE-6520, not only the vinyl group in the zirconia particle surface-modifying material and the hydrogen group in OE-6520 are bound to each other through a crosslinking reaction in the presence of platinum as a catalyst, but also the vinyl group and the hydrogen group in OE-6520 undergo an addition reaction, whereby the silicone resin-forming component is polymerized and cured in a state of keeping the dispersed state of the zirconia particle.
(Fabrication of Silicone Resin Composite)
[0173]The above-described silicone resin composition was cured by a thermal treatment at 150° C. for 3 hours, thereby obtaining a silicone resin composite.
[0174]The already-described various evaluations were performed by using this silicone resin composite. Incidentally, in the evaluation of gas permeability, the thickness of the sealing layer was made to be 500 μm.
Example A2
Fabrication of Zirconia Particle
[0175]A zirconia particle was fabricated in the same manner as that in Example A1.
(Fabrication of Surface-Modifying Material Containing Both a Phenyl Group and an Alkenyl Group)
Preparation of Surface-Modifying Material A: (CH2═CM(CH3)2SiO(SiO(C6H5)2)45Si(OC2H5)3
[0176]1.8 g of dimethyl vinyl silanol was dissolved in 60 mL of a tetrahydrofuran (THF) solvent in a nitrogen atmosphere, 1.2 g of n-butyl lithium dissolved in n-hexane was added dropwise at a temperature of 0° C. while stirring, and the contents were allowed to react with each other for 3 hours, thereby obtaining lithium dimethyl vinyl silanolate (see formula (A)).
[0177]Subsequently, a solution of 160.5 g of hexaphenyl cyclotrisiloxane dissolved in a THF solvent was added dropwise, and the contents were allowed to react with each other at a temperature of 0° C. for 12 hours, thereby obtaining lithium phenylvinyl organosilanolate (see formula (B)).
[0178]Subsequently, 3.6 g of chlorotriethoxysilane was added, and the contents were allowed to react with each other at a temperature of 0° C. for 12 hours (see formula (C)).
[0179]Subsequently, n-hexane was mixed to form a precipitate of lithium chloride, and thereafter, the lithium chloride was removed by filtration, thereby obtaining a surface-modifying material A containing both a phenyl group and an alkenyl group.
[0180]A structure of the obtained surface-modifying material was confirmed by means of 1H-NMR.
[0181]Here, an outline of the synthesis flow of the surface-modifying material containing both a phenyl group and an alkenyl group is shown below.
(Surface Modification on Zirconia Particle: Fabrication of Surface-Modified Zirconia Particle)
[0182]Subsequently, to 10 g of the zirconia particle, 80 g of toluene and 5 g of a methoxy group-containing phenyl silicone resin (KR217, manufactured by Shin-Etsu Chemical Co., Ltd.) were added and mixed, and the mixture was subjected to a surface modification treatment with a bead mill for 6 hours, followed by removing the beads. Subsequently, 3 g of the above-described surface-modifying material A was added, and the contents were subjected to surface modification and dispersion treatment under refluxing at 130° C. for 6 hours, thereby preparing a transparent dispersion liquid of zirconia particle having been surface-modified with a surface-modifying material having a phenyl group and a surface-modifying material having both a phenyl group and an alkenyl group (vinyl group).
(Fabrication of Silicone Resin Composition and Silicone Resin Composite)
[0183]A silicone resin composition and further a silicone resin composite were fabricated in the same manners as those in Example A1, except for using the above-described methoxy group-containing phenyl silicone resin and the transparent dispersion liquid of zirconia particle having been surface-modified with the surface-modifying material A, followed by performing the various evaluations.
Example A3
[0184]A silicone resin composition and further a silicone resin composite were fabricated in the same manners as those in Example A1, except for making the thickness of the sealing layer to be 30 μm, followed by performing the various evaluations.
Example A4
Fabrication of Titania Particle
[0185]242.1 g of titanium tetrachloride and 111.9 g of tin(IV) chloride pentahydrate were put into 1.5 L (liters) of pure water at 5° C., and the contents were stirred to fabricate a mixed solution.
[0186]Subsequently, this mixed solution was heated to adjust the temperature at 25° C., and an ammonium carbonate aqueous solution having a concentration of 10% by mass was added to this mixed solution, thereby adjusting a pH at 1.5. Thereafter, the resultant was aged at 25° C. for 24 hours, and thereafter, an excessive chloride ion was removed by means of ultrafiltration.
[0187]Subsequently, water was removed from the mixed solution after removal of a chloride ion by using an evaporator, followed by drying to fabricate a titanium oxide particle. The obtained titanium oxide particle had an average primary particle diameter of 4 nm.
[0188]A titania transparent dispersion liquid was fabricated by performing the surface modification, and subsequently, a silicone resin composition and further a silicone resin composite were fabricated in the same manners as those in Example A1, except for using the foregoing titanium particle, followed by performing the various evaluations.
Example A5
Fabrication of Silica Particle
[0189]80 g of methanol was mixed with 20 g of ammonia water having a concentration of 24%, 0.8 g of 10N—NaOH, and 4 g of a polyoxyethylene alkyl ether (a trade name: EMULGEN 707, manufactured by Kao Corporation) as a surfactant. 4 g of tetraethyl silicate (a trade name: ETHYL SILICATE 28, manufactured by Colcoat Co., Ltd.) diluted with methanol was added dropwise thereto. The mixed liquid was stirred at 20° C. for one hour. After completion of stirring, a precipitate was separated by means of decantation, and an operation of redispersion in methanol and decantation was repeated, thereby removing residual ions.
[0190]The obtained wet silica particle was dried under reduced pressure to dry the methanol, thereby obtaining a formed silica particle. The obtained silica particle had an average primary particle diameter of 4 nm.
[0191]A silica transparent dispersion liquid was fabricated by performing the surface modification, and subsequently, a silicone resin composition and further a silicone resin composite were fabricated in the same manners as those in Example A1, except for using the silica particle, followed by performing the various evaluations.
